Port of Tauranga, which acquired a half stake in Timaru's PrimePort last year, has extended its South Island reach with the acquisition of land south of Christchurch it plans to develop as a freight hub.

The nation's biggest export port has conditionally agreed with the Selwyn District Council to purchase 15 hectares of land in the Izone Industrial Park at Rolleston about 12 kilometres south of Christchurch, it said in a statement. The park is being developed for manufacturing, warehousing and logistics businesses and has "excellent road and rail connections," it said.

The intermodal freight hub will receive, pack and distribute containerised cargo, the port company said.

"Establishing an intermodal freight hub at Rolleston will provide South Island exporters the option to efficiently access Timaru and similarly, importers in the Christchurch area will have the option to ship through Timaru," the company said.

Port of Tauranga shares rose 0.5 percent to $13.80 and have edged up 2.2 percent in the past 12 months.